Piston pin by HC120807025045


									P R E S S R E L E A S E

                          Piston pin layering process

                          STUTTGART, September 2006 – The Stuttgart supplier MAHLE
                          coats piston pins with diamond-like layers, called DLC. DLC
                          stands for “diamond like carbon” and describes modern layer
                          systems increasingly used for components subject to high
                          tribological loads. Piston pins that are DLC-coated with layers
                          measuring only a few thousandths of a millimeter guarantee
                          minimum wear and maximum seizure resistance.

                          Combined properties of graphite, diamond and polymers

                          Is your engine subject to unfavorable lubricating conditions, and is
                          the bushing in the small connecting rod eye supposed to be
                          eliminated? This is where a coated piston pin will come in handy.
                          Eliminating the bushing offers the potential of reducing the
                          installation space of the entire crank gear and the moving mass. In
                          addition, a phosphate-treated bearing surface on the connecting rod
                          or on the steel piston may improve the run-in behavior of the parts.
                          DLC-layers are made primarily of carbon, however the atoms are not
                          oriented as those in a diamond, but instead exist as crystals in
                          random orientation. These layers combine the properties of graphite,
                          diamond and polymers. They significantly lower friction and in
                          general are extremely hard.

                          The properties of the DLC-layers can be designed such that the
                          layers, despite being very thin, tolerate extreme surface pressures
                          without resulting in the seizure of the pin. The layers can be
                          produced in a chemical vapor deposition process (PACVD –
                          plasma activated chemical vapor deposition) at relatively low
                          temperatures of less than 250ºC. Due to the low temperatures,
                          proven case-hardened steels can be used for the piston pins and
                          more complex nitrided steels can be avoided. Frequently, a
                          chromium nitride coating is applied beneath the DLC-layer. This
                          coating ensures minimal wear, even if the DLC-layer should be
                          worn through due to friction. Chromium nitride coating produced
with physical vapor deposition (PVD) methods act similar to the
DLC-layers, however are inferior in their effectiveness to prevent
seizing of the piston pin.

The MAHLE Group ranges internationally among the top 3 system
suppliers for piston systems, cylinder components, valve train
systems, air management systems and liquid management
systems. With its unique systems competency in the field of the
combustion engine and engine peripherals, MAHLE is a globally
leading development partner for the automotive and engine
industry. All established manufacturers of combustion engines are
customers of MAHLE.

With above-average enthusiasm for performance, precision,
perfection and unique innovation, MAHLE enhances the
development of vehicle and engine technique and keeps setting
benchmarks – for more than 80 years.

The company is locally present in all important markets of the
world. Approximately 37,500 employees are engaged in 80
production locations and in seven research and development
centers. More than 2,000 development engineers and technicians
worldwide are working on trend-setting concepts, products and
systems for the development of the combustion engine.

In 2006, the MAHLE Group expects a turnover of approximately
4.3 billion EUR and is therefore one of the 30 largest suppliers of
the automotive industry worldwide.

Birgit Albrecht
Corporate Communications/Public Relations
Pragstraße 26 - 46
D-70376 Stuttgart
Phone: +49 (0) 711/501-12506
Fax: +49 (0) 711/501-13700

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